David, I think it sounds like you did a wonderful job giving a practical perspective on training. I tend to fall in line with William's view that "Aikido" can be as practical as most (if not all) formalized systems..."Aikido" is hardly a homogeny. However, when I taught kids' class I tried to point out the inherently chaotic nature of "fighting" as a way of hedging over-confidence. I also liked to point out that, just because we have training, we aren't necessarily going to be more prepared than the other guy, even if that person has no training at all (formalized or otherwise)...moment-to-moment mind-set seems like a big factor to me, at any rate.

...And it seems to me the learning curve issue varies more based on who you're training with than in what you're training, so the idea "Aikido or not Aikido" seems moot to me.